that is the big challenge ahead of us. you just don't think of raw sewage in waterways in a developed country, and yet, that's what we have, and not just in pittsburgh, but all over. narrator: pittsburgh is situated at the confluence of the allegheny, monongahela, and ohio rivers. these three rivers are vital for industry, recreation, and drinking water. and each year, billions of gallons of combined sewer overflows discharge directly into those rivers. hecht: we're now having to face the consequences of the choice that was made to put in combined sewer systems. narrator: in 1994, the government adopted a combined sewer overflow policy to reduce csos nationwide. cities with combined sewer overflows now face an enforcement action called a consent decree. under a consent decree, a city must reduce pollution levels significantly within a strict time frame or face heavy fines. in 1960, the combined sewer overflows were a perfectly legitimate way of dealing with sewers. woman: the mind set was that, what did it matter if we wer